Articles (and/or compositions) are known that may be used as a sealant and void-filler to protect a substrate in a corrosive, moist and adverse environment. These articles and/or compositions include simple tape wrappings as well as heat-recoverable materials (see Cook et al U.S. Pat. No. 3,086,242). Other articles and/or compositions that are advantageously employed under appropriate conditions are oils, greases and adhesives.
A further important candidate for a sealant and void filler composition is an encapsulant e.g. a gel. Heretofore, gels have typically been prepared as a two-part liquid composition with ingredients that react slowly together. Before the ingredients have gelled the liquid composition is poured into a container that holds a substrate to be sealed; the liquid composition subsequently cures in situ to form a gel (see U.S. Pat. No. 4,375,521 and U.S. Pat. No. 4,102,716). This procedure is not optimal, however, since it involves preparation of the liquid composition at the site, and delay while the composition gels. Additionally, it is not always practical to deliver the gel to the substrate by way of the container. Furthermore, when reentry to the sealed substrate is required, the gelled composition cannot easily be removed.
Copending application Ser. No. 434,011 filed Oct. 12, 1982, by Christian A. Debbaut now U.S. Pat. 4,600,261, and the Continuation in part thereof, Ser. No. 504,000 filed 13 June, 1983, now U.S. Pat. No. 4,634,207, describe apparatus for providing a protective covering over a substrate, the apparatus comprising a support member and an encapsulant which adheres to the support member and has a cone penetration value of 100 to 350 (10.sup.-1 mm) and an ultimate elongation of at least 200%. Preferred encapsulants are gels formed by curing of suitable precursors, e.g. of polyurethanes or polysiloxanes, in the presence of suitable reactive or non-reactive extenders and plasticizers. The disclosures of these two applications are incorporated herein by reference.